James f



(No Model.)

J. F. GILLILAND.

INSULATOR FOR LINE WIRES OF MECHANICAL TELEPHONES. No. 296,330. PatentedApr. 8, 1884.

- 2 5 fore been impossible, for the reason that in the llNr'ra STATESPATENT FFIGE.

JAMES F. GILLILAND, OF INDIANAPOLIS, INDIANA, ASSIGNOR TO JOHN B.

BENNETT AND AUGUST B. MEYER, BOTH OF SAME PLACE.

INSULATOR FOR LINE-WIRES OF MECHANICAL TELEPHONES.

SPECIFICATION forming part of Letters Patent No. 296,330, dated April 8,188%.

Application filed June 26, 1883. (No model.)

To (ZZZ whom it may concern:

Be it known that I, J AMES F. GILLILAND, of the city of Indianapolis,county of Marion, and State of Indiana, have invented certain 5 new anduseful Improvements in Insulators for Line-WVires of MechanicalTelephones, of which the following is a specification.

The object of my said invention is to produce an insulator or means ofsuspension for the line-wire of mechanical telephones which will confinethe voice sounds to the wire, and also prevent said wire from taking upother sounds from the objects to which it is secured. This object isaccomplished by constructing I 5 such an insulator composed of a pieceof wire or cord and apiece of dense non-resonant material attachedthereto and held in close contact therewith.

One great advantage arising from the use of my insulators or means ofsuspending the linewire is that it is possible to bind said line-wiretightly with the wire forming part of said insulators without destroyingor impairing its capacity to transmit sound. This has heretotransmissionof sound by the mechanical vibration of the wire the sound, or aconsiderable portion thereof, will leave the wire at the first point towhich it is firmly attached, un-

0 less cut off in some way, and previous means of suspension, being asgood conductors of sound as the wire itself, have been practicable onlywhen attached to the wire loosely.

My means of suspension, being composed in 3 5 part of dense non-resonantmaterial, cuts off the sound from the wall or post to which it issecured, and therefore may be connected firmly to the wire. By thismeans the line-Wire may be drawn tight and securely fastened to each 0point of attachment before proceeding to the next, which is a greatconvenience in stringing wires, especially long wires.

Referring to the accompanying drawings,

which are made a part hereof, and on which similar letters of referenceindicate similar parts, Figure 1 is a general view of apparatusembodying my improved insulator as I prefer to make it; Fig. 2,a detailview of the insulator on an enlarged scale; Fig. 3, a view of an alter--nate construction; and Fig. 4., aview similar to Fig. 3, except thatone-half the insulator is removed. 1

In said drawings, the portions marked A represent the line-wire of amechanical telephone; B, the wire forming part of the hanger, and O theinsulator proper, or piece of nonresonant material,forming the otherpartthereof. The line-wire A connects the telephones in the usualmanner. It forms no part of the present invention, though I prefer touse the wire described in Letters Patent No. 255,174. issued to James A.Lakin under date of March 21, 1882, or an improved wire devised bymyself, rather than the common kind, as it produces better results.

The wire or cord portion B of the hanger is preferably the same kind ofwire as the wire A. It is attached to said wire A at one end, and to abracket, B, upon the poles, buildings, or Whatever structure forms asupport for the line.

The insulator proper, or piece of non-resonant material, C, is usuallyof cast metal, and preferably of substantially the form shown in Fig. 2.In this case the wire B is looped around the wire A, passed through theeye a of said insulator, around the body thereof, through the eye 0, andto the bracket B, where it is secured. In the alternate constructionshown by Figs. 3 and 4 the wire is passed from the wire A to the bracketB, as before; but the insulator 0, being in two pieces, is applied byplacing one piece on each side of the wire, and then securing saidpieces together by screws 0, as shown.

The operation of my said inventiomas proved by many and varied practicaltests, is to cut off those sounds which, in the ordinarily-constructedmechani oil-telephone lines, have come in from the poles, &c., and havebeen the source of so much annoyance, and to prevent the voice sounds,which it is desired should be conveyed, from passing off or becomingdissipated during the course of transmission.

It will be readily seen, upon an examination of the drawings, that theinsulator Cis a dead weight upon the hanger B, and is not placed intension at all. Almost any material in this position is calculated tointerrupt sound more or less effectively, and nearly all materials to agreat degree. By selecting the material (cast metal and especiallycast-lead I have found superior for the purpose) the sound is so nearlyentirely interrupted as to practically perfectly insulate the wire fromthe structure to which it is suspended.

Having thus fully described my said invention, what I claim as new, anddesire to secure by Letters Patent, is

1. The combination, with a mechanical-telephone line-wire and thestructures by which it is supported, of a hanger composed of wire orcord running from said 1ine-wire to said structure, and an insulatorsecured to said wire

